I was in Home Depot a couple of days ago (in Western Massachusetts). Crappy 19/32 CDX was $85 for a 4x8 sheet. Sitting right next to it was 3/4" oak veneer at $60. I think it would be pretty funny to sheath a house in sort of cabinet grade plywood (it is 7 ply Purebond which usually has a couple of voids per sheet).
Those are definitely not substitutable. In addition to the difference in glues the peer comment notes (the oak plywood will likely delaminate if exposed to moisture), you need to sheathe a house in a product rated for that use. That oak veneer doesn't have a span rating stamped on it, so any inspector would fail you.
